Wire and cable extruder operation, maintenance and maintenance
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Duplex Fittings,Duplex Pipe Fitting,Duplex Stainless Steel Pipe Fitting,Duplex Butt Welded Fitting Zhejiang Max Stainless Steel Co.,Ltd , https://www.cnstainlesstube.com
The use of screw extruder includes a series of links such as installation, adjustment, commissioning, operation, maintenance and repair of the machine. The use of the screw extruder has the common features of the general machine, mainly in terms of drive motors and speed-reduction transmissions. However, the working system of the screw extruder, that is, the extrusion system, has unique characteristics. Special attention should be paid to the characteristics of the extruder when using the screw extruder.
The installation, adjustment, and commissioning of the machine are generally specified in the extruder's instruction manual. The operating methods, maintenance and maintenance of the extruder are briefly described here:
First, the operating method <br> <br> operator of the extruder must be familiar with their structural characteristics extruder operated, especially correctly grasp the structural characteristics of the screw, heating and cooling characteristics of the control instrument, and head characteristics Assembling conditions, etc., in order to correctly grasp the extrusion process conditions, the correct operation of the machine.
The method of extruding different plastic products is different, but there are also similarities. The following is a brief description of the same procedures and operations that should be taken into account when extruding various products.
1. Preparation before driving (1) Plastic for extrusion molding. The raw materials should meet the required drying requirements and, if necessary, further drying. The raw materials were sieved to remove agglomerates and mechanical impurities.
(2) Check whether the water, electricity, and gas systems in the equipment are normal, ensure that the water and gas lines are unobstructed, leak-proof, whether the electrical system is normal, whether the heating system, temperature control, and various instruments work reliably; Operation, observe whether the equipment is operating normally; start the vacuum pump of the setting table and observe whether the work is normal; add lubricate on the smooth parts of various equipment. If you find a fault, remove it in time.
(3) installed head and styling sleeve. According to the product variety, size, select the head specifications. Install the head in the following order.
1 The head should be assembled together and mounted on the extruder as a whole.
2 Before assembling the handpiece, the grease applied during storage should be wiped off, and the surface of the cavity should be carefully inspected for scratches, scratches, and rust. The necessary polishing is performed, and then a silicone oil is applied to the surface of the flow path.
3 Sequentially assemble the various parts of the machine head. Apply high-temperature grease to the threads of the bolts, and then tighten the bolts and flanges.
4 Place the perforated plate between the flanges of the machine head to ensure that the perforated plate is compacted without flashing.
5The horizontal position of the die should be adjusted before the tightening bolts of the coupling flange of the machine head and the extruder are tightened, and the level of the square head can be adjusted horizontally. The round nose is based on the bottom of the fixed model rubber and used as the reference. The bottom surface of the mold is leveled.
6 Tighten the flange bolts, tighten the head bolts, and install the heating ring and thermocouple. Note that the heating ring should be tightly attached to the outer surface of the nose.
7 Install the calibrator and adjust it in place. Check if the center line of the main machine, calibrator and tractor is aligned. After adjustment, tighten the fixing bolts. Connect the sizing jackets to the water and vacuum tubes.
8 Turn on the heating power and heat evenly the head and the machine. At the same time open the hopper bottom and the gear box cooling water and exhaust vacuum pump inlet valve. When the heating temperature rises, the temperature of each stage is first adjusted to 140°C. When the temperature rises to 140°C, the temperature is maintained for 30-40 minutes, and then the temperature is raised to the temperature during normal production. When the temperature rises to the temperature required for normal production, it is maintained for about 10 minutes so that the temperature of the various parts of the machine tends to stabilize before it can be driven. The length of holding time differs depending on the type of extruder and the type of plastic material. Insulation for a period of time so that the temperature inside and outside the machine is consistent, so as not to indicate that the temperature of the instrument has reached the required temperature, but the actual temperature is low. If the material is put into the extruder at this time, the actual temperature is too low and the material melt viscosity is too large. Causes an overload in the axial force and damages the machine.
9 Feed the raw materials used for driving into the hopper for use.
2, drive (1) can be driven at a constant temperature, before driving the head and the extruder flange bolts should be tightened once again to eliminate the difference between the thermal expansion of the bolt and the head, tightening the order of the head bolt is diagonally tightened Use uniform force. When tightening the head flange nut, it is required to be tight and tight all around, otherwise run out of material.
(2) Drive, press the "Ready to drive" button, then "drive" button, then slowly rotate the screw speed adjustment knob, screw speed slow start. And then gradually speed up, while a small amount of feed. When adding materials, pay close attention to the changes of the indicators of the host current meter and various indicator headers. Screw torque can not exceed the red mark (usually torque table 65% -75%). Before the plastic profiles are extruded, no one can stand in front of the die to prevent accidents caused by broken bolts or wet foam due to raw materials. After the plastic has been extruded from the die, it is necessary to cool the extrudate slowly, introduce the traction device and the sizing die, and start the devices. Then according to the indicated value of the control meter and the requirements for the extruded product. Adjust each part accordingly so that the entire extrusion operation is normal. And according to the need to add foot material, twin-screw extruder using a measuring feeder uniform feeding at equal speed.
(3) When the die is discharged uniformly and the plastic is good, the styling sleeve can be hauled. Judgment of the degree of plasticity depends on experience, generally can be judged according to the appearance of the extruded material, that is, the surface is shiny, no impurities, no foam, coke material and discoloration, squeezed out by hand to a certain extent does not appear Burrs, cracks, and a certain degree of elasticity indicate that the materials are well plasticized. If the plasticization is poor, the screw speed, barrel and head temperature can be adjusted properly until the requirements are met.
(4) In the process of extrusion production, it is necessary to periodically check whether the various process parameters are normal according to the process requirements and fill in the process record sheet. Examine the quality of profile products according to quality inspection standards, and identify problems and take timely solutions.
3, parking (1) stop feeding, the extruder plastic squeezed out, when the screw is exposed, close the barrel and head power supply, stop heating.
(2) Turn off the extruder and auxiliary power supply to stop the screw and auxiliary machine.
(3) Open the head coupling flange and remove the head. Clean the perforated plate and the various parts of the head. To prevent damage to the inner surface of the head during cleaning, the residual material in the head should be cleaned by steel and steel. Then, the plastic adhered to the head should be ground with sandpaper, polished, and painted with oil or silicone oil. rust.
(4) After cleaning the screw and barrel, after removing the head, restart the host, add the parking material (or crushing material), and clean the screw and barrel. At this time, the screw adopts low speed (sr/min) to reduce the wear. After the material to be crushed is completely crushed into a powder, the residual pellets and powder may be repeatedly blown out from the charging port and the exhaust port by using compressed air until no residual material remains in the barrel, and then the screw speed is reduced to zero and the extrusion is stopped. Machine, turn off the main power and cold water total valve.
(5) The safety items that should be noted when extruding are: electrical, thermal, mechanical rotation, and loading and unloading of heavy parts. Extruder workshop must be equipped with lifting equipment, dismantling heads, screws and other bulky parts to ensure safe production.
Second, care and maintenance of the extruder screw extrusion system uses <br> <br> daily and periodic maintenance of two ways maintenance.
(1) Routine maintenance is a regular routine. It does not take up equipment work hours and is usually completed during driving. The focus is to clean the machine, lubricate all moving parts, fasten loose screws, check and adjust electric motors, control instruments, working parts and pipes etc. in time.
(2) Regular maintenance is usually performed after the extruder has been continuously operated for 2500-5000 h. The machine needs to dismantle the inspection, measure and identify the wear of the main components, replace the parts that have reached the specified wear limit, and repair the damaged parts.
(3) Empty vehicles are not allowed to operate, so as to avoid screw and machine slips.
(4) If abnormal sound occurs during operation of the extruder, stop it immediately for inspection or repair.
(5) Prevent metal or other debris from falling into the hopper so as not to damage the screw and the barrel. In order to prevent iron debris from entering the barrel, magnetic absorption parts or magnetic frames may be installed at the entrance of the material to the feeding port of the barrel to prevent debris from falling. The material must be sieved in advance.
(6) Take care that the production environment is clean. Do not allow the trash and impurities to be mixed with the material to block the filter plate. This will affect the product yield, quality, and increase the head resistance.
(7) When the extruder needs to be stopped for a long time, anti-rust grease should be applied on the working surfaces of the screw, machine frame, and machine head. The small screw should be hung in the air or placed in a dedicated wooden box and flattened with wooden blocks to avoid screw deformation or bumps.
(8) Periodically calibrate the temperature control instrument to check its adjustment accuracy and control sensitivity.
(9) The reducer maintenance of the extruder is the same as that of a normal standard reducer. It mainly checks the wear and failure of gears, bearings, etc. The gearbox should use the lubricating oil specified in the manual of the machine, and add the oil according to the specified oil level. The oil is too little, the lubrication is not reversed, and the service life of the parts is reduced; the oil is too much, the heat is high, the energy consumption is much, the oil is easy. Deterioration also causes the failure of lubrication, causing damage to parts. The seal gasket (ring) should be replaced in time to ensure the amount of lubricating oil.
(10) The inner wall of the cooling water pipe attached to the extruder is susceptible to scaling and is susceptible to corrosion and rust. Careful inspection should be done during maintenance. Excessive scale can block the pipeline and can not achieve cooling effect. Corrosion can cause serious leakage. Therefore, cleaning and anti-corrosion measures must be taken during maintenance.
(11) For the DC motor with the drive screw rotating, it is necessary to check the wear and contact of the brush. Check whether the insulation resistance of the motor is higher than the specified value. In addition, check the connection lines and other components for rust, and use protective measures.
(12) Designate someone to take care of the equipment maintenance. The detailed records of each maintenance and repair are included in the plant equipment management file.
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